I would have to agree that the bolt weapons do feel a bit underpowered. Shooting a Majoris level enemy 30+ times in the face is unacceptable on any difficulty... Especially since headshots don't even stagger those enemies even with consistent fire. I just started using the heavy bolt rifle and I've finally made it to the third tier of that weapon and still its underwhelming when dealing with Majoirs and above level enemies. I will say though, I've become a headshot master due to this because it will take out every Minoris level enemy with one headshot. I can clear waves of enemies even on substantial difficulty but those Majoris are just a pain to take on. If they didn't want to buff the bolt weapons then at least make consistent headshots stagger the enemy, 5-7 or 8ish seems like a reasonable request. That way your not taking damage from the same guy your trying to take down. It's extremely annoying when I'm pelting a Majoris in the face consistently and having to dodge their fire (especially the flamethrower chaos marines) when it takes so many hits to kill them. Unfortunately this will not probably get fixed any time soon since they've already addressed some of the requests on this forum and overlooked that enemies need to be staggered from headshots (not just sniper headshots)...

Bolt weapons are THE iconic 40K weapon, yet they are so weak until you get them all the way levelled up.  They need to be improved so they are actually viable.  On Tatical its either Melta or Plasma, and while both of these should be better than bolt guns, they shouldnt leave boltguns in the dust.

They shouldn't really be 'better.' They should be different. But melta is going to be better right now because the health glitch. But it's going to get you killed, likely, when it's fixed. Not to mention it's functioning like a heavy flamer/melta combo because of the sheer numbers in the swarm it kills. 

Add a pinning mechanic to full auto where hordes slow when x number of bullets hit enemies within a range. 

Allow pinned enemies to be instagibed in melee. 

Heavy Bolter is a zone control, and there's nothing letting it be that. I mean, it's also extremely killy. Might consider making those rounds a little more explosive. 

Point 1) A "pinning feature" to hordes for bolt guns would be a good start where rounds slow enemies. This also supports Team Play big time.

Point 2) Considering bolt weapons are supposed to be like rockets, they probably should deal more damage as well...

Bolters indeed feel weak. The only one worth running is the une with the grenade  launcher because of it. I get it, elites (Majoris/Extremis) shouldn't die from like 2 shots but why trash units (Minoris) can tank 2-4 shots from is beyond me.
Speaking of elites, okay, they are meant to pose threat and are no pushovers, but they also shouldn't facetank ike 30ish bolter rounds.
Heavy Plasma on the other hand was owning before the patch already, now it's just absurd. All it needed was a little ammo buff and less heat generated, now it destroys everything as long as it has ammo. Oh chaos spawning in? PEW - Gone.....and I say this as someone who loves plasma weapons in the 40k Universe.